18.08.192 Landslide and erosion hazard areas.
Areas which are identified as landslide or erosion hazard areas shall be subject to the requirements established in this section.
A. Regulation. Applications for regulated activities proposed within designated landslide and erosion hazard areas shall be accompanied by a geotechnical report prepared by a geologist or geotechnical engineer licensed as a civil engineer with the state. If it is satisfactorily demonstrated to the director that a landslide or erosion hazard potential does not exist on the site, the requirements of this section may be waived.
B. Geotechnical Report Requirements. A geotechnical report required under this section shall include, at a minimum, the following information:
1. Topographic data at a minimum scale of 1:240 (1 inch equals 20 feet). Slope ranges shall be clearly delineated in increments of 15 percent to 25 percent, 25 percent to 40 percent and greater than 40 percent;
2. Subsurface data, including boring logs and exploratory methods, soil and rock stratigraphy, ground water levels and any seasonal variations of ground water levels;
3. Site history, including description of prior grading and clearing, soil instability or slope failure.
If a geotechnical report has been prepared and accepted by the director within the previous two years for a specific site and the proposed land use development and site conditions have not changed, the report may be utilized without the requirement for a new report.
C. Development Standards. Upon submission of a satisfactory geotechnical report or assessment, site development may be authorized by the director subject to the following:
1. Buffers shall comply with the requirements of GHMC 18.08.190(A);
2. Approved erosion control measures are in place prior to, or simultaneous with, site clearing or excavation;
3. Such other conditions as deemed appropriate by the administrator to ensure compliance with the provisions of this chapter. (Ord. 1245 § 36, 2012; Ord. 1036 § 33, 2006).